Solo is too ambitious, serving more as an origin story than a good adventure story. The movie starts on Corellia where Han (Alden Ehrenreich) is a low level goon in a criminal underworld ruled by a swamp dragon. He is in love with Qi'ra (Emilia Clarke). They try to escape but she is caught. Han is forced to join the Empire and enrolls in flight school. However, next we see him, he is a grunt on some random planet, rating somewhere below a storm trooper. Trying to go AWOL, he is caught and tossed into a cage with the beast. He sees the remains of the beast's previous victims. The beast proves to be Chewbacca and Han speaks just enough Wookiee to join forces to escape. Next, the pair join Beckett (Woody Harrelson) and his band of rogues. Beckett needs to get his hands on some coaxium, a miracle fuel. They go to yet another planet where they try to hijack a coaxium shipment but everything goes sideways when a rival band intervenes. Beckett takes them to another planet to meet with Dryden Vos (Paul Bettany) to work out another means of delivering the promised coaxium. To his amazement, Han encounters Qi'ra there! With Qi'ra now joining them, Beckett, Han, and Chewie recruit Lando Calrissian (Donald Glover) and his crazy android, L3-37. They fly to Kessel, where coaxium is mined. The Kessel run requires a circuitous 20 parsec flight path to navigate a dangerous nebula. Han took a shortcut on the way out, thus his claim of doing the Kessel Run in 12 parsecs. The movie has more twists and turns to go after that. There is too much to digest.
There are a series of villains and the story can't settle on one overarching bad guy. We start with the swamp dragon and her minions, move onto the Empire that he is trying to abandon, then there are the rival raiders, Dryden Vos, slavers, and more still. Dryden is the closest to a main villain but he is introduced late and has a worse bark than bite. Combined with the constant change of venue and the series of 'jobs' that almost always fail, it contributes to the lack of focus.
Han comes across as hapless. Pretending a rock is a thermal detonator was cheesy. Why is he a pro at Star Wars poker? We've had no hint that he is a good gambler prior to his joining the card game. That he later walks in and trounces everyone makes you wonder why he doesn't just become a gambler rather than risk being a smuggler. The way Han wins the Millennium Falcon from Lando is much different from what I had pictured based on the comments in The Empire Strikes Back. Han repeatedly tries to talk his way out of things and it fails miserable, mostly humiliating our hero. Once, okay. But it happens several times.
Beckett was the best character of the bunch. He is kind of like Han Solo from Star Wars (1977), so it is unsurprising that he serves as a mentor to Han. And like Han, he is beset by bad luck. Where future Han is in hock to Jabba, Beckett is in hock to Dryden Vos. Looks like Han chose the wrong mentor. Yeah, yet another bad move by young Han.
Qi'ra is a mystery that is not solved. Exactly what happened to her in the years since Han left her on Corellia is implied but not spelled out. She repeatedly tells him that she has changed though he doesn't take her word for it. Her ambition outweighs any feelings she has for Han, which dampens the romance qualities of their relationship. Han is deluding himself that they have a future, showing yet again that he is clueless.
L3-37 is annoying from her first appearance. Look, it's a droid that wants equal rights and jeopardizes the mission because of it. Now that we have successfully infiltrated, how about I remove the restraining bolts from every droid and encourage them to revolt. So much for stealth. She entirely earns being blasted. Lando risks life and limb to rescue the remains and has to 'save' her by integrating her with the Falcon. Um, shouldn't you just need to get replacement parts? Chewie was able to reassemble C3PO in The Empire Strikes Back.
In the end, Han aids the seeds of the rebellion, putting him in the good guy camp because he needs to demonstrate selflessness. That undermines his transformation in the original trilogy. He's been a rebel sympathizer all along. Heck, he infused them with a huge fortune when Luke and Leia were children.
The movie ends with a clear intent for a sequel. Han and Chewie plan to go to Tattooine and do a job for one of the Huts while Qi'ra is off to join the leader of Crimson Dawn, none other than Darth Maul. Based on the box office, that presumed sequel may not come to pass. Ron Howard should have streamlined this movie and cut as much of the non-essentials as possible. Make it a stand alone adventure story that doesn't have a constantly rotating cast of characters.
Fun but not great.